This SBIR project is designed to develop thermo-responsive nanofibers as microcarriers for cell culture. Nanofiber surfaces provide a more in vivo like growth surface for mammalian cell growth and function. The use of thermo-responsive polymer allows the cells to be released from the substrate in a gentle, non-invasive, and less cumbersome fashion compared to trypsin or other digestive enzymes. This method of cell detachment eliminates the use of animal products in the cell culture process, which is a major cause of concern for pharmaceutical manufacturing processes. This Phase II project describes the synthesis and fabrication of microcarriers from nanofibrillar and thermo-responsive materials for the large scale cultivation of anchorage dependent animal cells. Furthermore, a magnetic thermo-responsive microcarrier is also described to aid in the separation of cells from the culture system. This phase II project is expected to make the use of microcarrier culture more efficient for large scale production of vaccines, recombinant proteins, and cells for therapy, etc. Specific aims of this Phase II proposal include: 1) Fabricate thermo-responsive nanofibers into microcarrier discs;2) Optimize the use of thermo-responsive microcarriers for cell culture by evaluating growth of three different cell types;3) Compare and evaluate the efficiency of thermo-responsive microcarrier versus widely used commercially available microcarriers;4) Synthesize magnetic microcarriers and optimize their use in cell and microcarrier suspension separation. PUBLIC HEALTH RELEVANCE: Basic research and industrial biopharmaceutical production processes using animal cells have a number of safety and technical requirements, such as defined media devoid of substances from animal origins, standardization, high product yield, high product concentration, scale-up potential, etc. Microcarrier based processes fulfill a number of these requirements. In microcarrier culture, cells grow either on the surface of small spheres or as multilayers in the pores of porous structures that are usually suspended in culture medium by gentle stirring. Microcarriers offer a much higher surface area to volume ratio and therefore they have been used extensively for amplifying various types of adherent cells for the expansion of cells for large scale production of growth factors, vaccines, and antibodies. The use of microcarriers is also gaining acceptance in the stem cell research for generating large quantities of cells for cell therapy applications. Cell culture industry is now a significant foundation of the $30 billion annual biopharmaceutical market. As the use of vaccines, monoclonal antibodies, thrombolytics, interferons, blood factors, recombinant proteins and therapeutic enzymes increases, the size of the market that uses mammalian cell culture as the primary method of producing these biopharmaceuticals will also grow.